It may well be because Tony Blair has Palestine on his conscience that he took the thankless role of special envoy to that benighted land. When we invaded Iraq, Blair made clear that reconciling Israel and Palestine was the twin challenge. His government failed to rise to it. The road map to nowhere has been compounded by a lack of even-handedness, a want of political imagination and a subservience to Israel and the Bush administration. That has directly contributed to the tragic shambles that is Palestine today. The old Israeli right-wing policy of perpetual divide and rule is again triumphant.

My third personal fact-finding visit to Palestine since 2003 ended a few weeks ago with a one-to-one meeting with Ismail Haniyeh, then Prime Minister. Britain's refusal to engage with Hamas over its lack of democratic legitimacy is seen there as wholly cynical, given that the boycott continued after elections last year gave them more than 60 per cent of the legislative seats.

Blair will find the Palestinians feel bitterly about the West's failure to stop Israel building its illegal wall, its rapid colonisation of the West Bank and the humiliation of the checkpoint. When I remarked to some Jewish NGO workers that the pass system seemed Kafkaesque, they said they called the West Bank 'Kafkastan'.

Israel's retention of £750m of Palestinian revenues and its wanton destruction of remaining Gaza infrastructure last year are further abuses over which we wring our hands. The expanding colonisation, of course, gives the lie to Israel's 'security-first' policy, because it is the greatest provoker of Palestinian desperation. None of this belittles or excuses Palestinian terror. But even that is a two-way street. Israel kills, on average, at least four Palestinians - mostly civilians - for every one of its own killed by Palestinians.

I urged Haniyeh to deprive Israel and the US of their main justification for this oppression, namely Hamas's refusal to recognise Israel. But he presides over a wide and vulnerable coalition beyond which are extremist groups, one of which holds Alan Johnston. It took courage for him to offer Fatah a unity government, and its inability to demonstrate to internal critics any practical dividends starve it of the authority essential to restore internal order and justice. It was also the former unity government's policy to achieve a two-state solution, which assumes a permanent Israel.

I told the Foreign Office of my conviction that the unity government was teetering and, if it failed, much worse would follow. I wish I had been wrong. New elections in Palestine could easily entrench Hamas in power. What then? Not only does Israel possess supremacy of military power, but it has a similar preponderance of 'corridors-of-power' advocacy in the West.

Despite the efforts of the recently formed Independent Jewish Voices network, the main Jewish influence has tended to bias British policy in a way that is likely to jeopardise the long-term interests of Israel. Against this background Blair will be expected to perpetuate divide-and-rule tradition and cold-shoulder Hamas. But he should be bold, in the way he was in Ulster.

He will need all his connections and experience to make progress. I hope he does, for all our sakes.